In a 100 m race, A runs at a speed of 5/3 m/s

In a 100 m race, A runs at a speed of 5/3 m/s. If A gives a start of 4 m to B and still beats him by 12 seconds, what is the speed of B?

  1. 5/4 m/s
  2. 7/5 m/s
  3. 4/3 m/s
  4. 6/5 m/s

Answer

Distance = Speed × Time

Let time taken by A to complete the race be t seconds.

100 = 5/3 × t

t = 60 s

Time taken by B = 60 + 12 = 72 s

Distance traveled by B = 100 - 4 = 96 m

Speed of B = 96/72 m/s = 4/3 m/s

The correct option is C.